The development of information storage technology is an embodiment of the progress of human civilization. From the invention of transistors to the advent of integrated circuits, human usher in a glorious era of information. The rapid development of information technology drives storage technology to rapidly develop towards non-volatile, high speed, low operation power consumption and good cycling performance. As a mainstream non-volatile storage technology used at present, flash memory has been widely used. However, with the rapid development of integrated circuits, disadvantages, such as limited number of cycles, slow operating speed and high operating voltage, of the flash memory limit its further application. Therefore, searching for a new generation of non-volatile memory has become the only way to improve information technology.
Due to the advantages, such as high-speed reading, high times of cycle, non-volatile, small component size, low power consumption, strong vibration resistance and radiation resistance, phase change memory is regarded by the International Semiconductor Industry Association as the most likely substitute for the present flash memory to become a device that will be the mainstream of future memory products and the first to become a commercial product.
The basic principle of a phase change memory is using the reversible transformation between high resistance (amorphous state) and low resistance (crystalline state) of a memory material in a device to achieve storage of “1” and “0.” Multi-level storage can be realized by using electrical signals to control the continuous changes of the high resistance of a memory material, such that the information storage capacity of a memory can be greatly improved.
Common phase change memory material system is tellurium-based material, such as Ge—Sb—Te, Si—Sb—Te, Ag—In—Sb—Te. In particular, GST (Ge—Sb—Te) has been widely used in phase change optical disks and phase change memories. But following problems exist as well: 1, the crystallization temperature is low; the crosstalk problem between adjacent cells in the chip display is serious, which may result in the risk of data loss and restrict its application; 2, the thermal stability thereof is not good, and data retention cannot be guaranteed; 3, the speed of phase change needs to be further improved; studies have shown that the electrical pulse to achieve a stable RESET operation based on the GST-based phase change memory is at least 500 nanoseconds, which does not meet the speed requirements of dynamic random access memory. Storage material with a faster phase change speed is therefore required.
Thus, how to provide a phase change material having a better thermal stability, a faster phase change speed and a smaller operating current, and being beneficial for increasing the cycle operating life of a phase change memory based on the material is a problem to be solved by current technical field.